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# fontSize

The font size for rendering a book.

```
var fontSize: some AssistantSchemas.Enum { get }
```

## Overview

Use Swift macros that generate additional properties and add protocol conformance
for your app enum implementation. The following example shows an app enum that conforms to the `.books.fontSize` schema:

```swift
@AppEnum(schema: .books.fontSize)
enum BookFontSize: AppEnum {
    case `default`

    static var caseDisplayRepresentations: [BookFontSize: AppIntents.DisplayRepresentation] = [
        .`default`: "Default",
    ]
}
```

For more information about the `.books` app intent domain,
see [Books](/documentation/AppIntents/app-schema-domain-books).
For general information about app intent domains, see [Making actions and content discoverable by Apple Intelligence](/documentation/AppIntents/making-actions-and-content-discoverable-by-apple-intelligence).

---

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